介入放射治疗(近距离放射治疗)已成为治疗早期鼻前庭肿瘤的新治疗标准;实际上,它允许高局部控制率和低毒性。然而,由于越来越多的患者将接受介入放射治疗(近距离放射治疗)作为主要治疗,希望实施新的策略来减少对有风险的器官的剂量,未来的目标是进一步降低长期副作用.
方法:我们能够确定两种不同的策略,以减少剂量到治疗量,包括植入技术(植入物可以是间质的,腔内或混合,导管可以使用巴黎系统规则或解剖学方法放置)和植入物内的剂量分布(最常用的参数是剂量不均匀比)。随后,我们提出了两种新策略来减少对有风险器官的剂量,包括像眼睛一样使用金属护罩固定器官,以及使用口腔拭子推开移动器官,在下颌骨的情况下。我们使用两种不同的算法来验证值,即TG-43和TG-186。
结果:我们提供了关于降低治疗体积毒性的策略的准确文献综述,强调所有植入技术的利弊以及使用剂量不均匀性比率。关于减少危险器官剂量的创新策略,我们在连续3例患者中使用两种不同的算法进行创新计算,调查了眼罩和拭子推开下颌骨的使用情况.我们的结果表明,剂量减少,在下颌骨和眼睛屏蔽的情况下,具有统计学意义。
结论:现有文献强调的最佳植入技术和剂量不均匀性比率的正确知识是强制性的,以降低治疗体积内的毒性。关于减少对处于危险中的器官的剂量,我们已经证明,使用眼罩和口腔拭子可以在临床实践中发挥关键作用;事实上,它们可有效降低对周围器官的剂量,并且不需要对当前的临床工作流程进行任何更改。
Interventional radiotherapy (brachytherapy) has become the new therapeutic standard in the management of early stages nasal vestibule tumors; in fact it allows for high local control rates and low toxicity profiles. However, since more and more patients will receive interventional radiotherapy (brachytherapy) as primary treatment, it is desirable to implement novel strategies to reduce the dose to organs at risk with the future aim to result in further lowering long-term side effects.
METHODS: We were able to identify two different strategies to reduce dose to the treatment volume, including the implantation technique (the implant can be interstitial, endocavitary or mixed and the catheters may be placed either using the Paris system rules or the anatomical approach) and the dose distribution within the implant (the most commonly used parameter to consider is the dose non-uniformity ratio). We subsequently propose two novel strategies to reduce dose to organs at risk, including the use of metal shields for fixed organs as in the case of the eyes and the use of a mouth swab to push away mobile organs, such in the case of the mandible. We used two different algorithms to verify the values namely the TG-43 and the TG-186.
RESULTS: We provided an accurate literature review regarding strategies to reduce toxicity to the treatment volume, underlining the pros and cons of all implantation techniques and about the use dose non-uniformity ratio. Regarding the innovative strategies to reduce the dose to organs at risk, we investigated the use of eye shielding and the use of swabs to push away the mandible by performing an innovative calculation using two different algorithms in a series of three consecutive patients. Our results show that the dose reduction, both in the case of the mandible and in the case of eye shielding, was statistically significant.
CONCLUSIONS: Proper knowledge of the best implantation technique and dose non-uniformity ratio as highlighted by existing literature is mandatory in order to reduce toxicity within the treatment volume. With regard to the dose reduction to the organs at risk we have demonstrated that the use of eye shielding and mouth swab could play a pivotal role in clinical practice; in fact, they are effective at lowering the doses to the surrounding organs and do not require any change to the current clinical workflow.